Encoding of meter readings for use in remote meter reading and telemetry systems are well known. In remote utility meter reading systems, encoding at the meter permits the electrical signal representation to be compared to the register dial reading at the meter site. The registers provide a totalizing or accumulating of the consumption of a measured quantity, such as kilowatt hours of electrical energy in a watthour meter, by converting the sum of rotations of a meter shaft into calibrated dial readings. The angular positions of each of the dial pointer shafts are converted into an electrical binary or digital signal. Watthour meter registers are typically provided with four or five dials each having an associated pointer shaft which is driven by a gear train system from the rotating metering movement. The five dials, for example, have readings in units, tens, hundreds, thousands and ten-thousands of the quantity to be measured, for example, kilowatt hours. The register has a predetermined ratio constant which is related to the consumption of the quantity to be measured and the rate of rotation of the metering movement.
In patent application Ser. No. 645,165, filed Dec. 30, 1975 and assigned to the assignee of this invention, there is disclosed and claimed an opto-electronic meter register encoder wherein a pattern disc is mounted to each of a plurality of pointer shafts. The pattern discs actuate photosensitive pickups to produce a plural bit binary code representation of the angular position of each pointer shaft. In accordance with the known construction of meter registers, the pointer shafts are interconnected by gearing so as to have a predetermined ratio such as a ratio of 1 to 10. In a five dial decade register the unit's dial will rotate ten-thousand times for a one-tenth incremental rotation of the ten-thousands dial. The thousands, hundreds and tens dials will be moved proportionally less along with movement of the lowest and highest order dials.
In the manufacture and maintenance of the meter encoding registers it is necessary to precisely establish and maintain the position of each pattern disc relative to each pointer shaft with which it is associated. The pattern discs are assembled to the shafts which are then assembled into the register gear train system. Finally, the pointers are oriented on the ends of the pointer shafts with respect to the position of the code disc and the dial indicating position of the pointer.
During manufacture it may be necessary to test and adjust the code discs so that they produce the appropriate electronic coded signal output for indicating the dial position of the shaft and pointer. Although the pointer may be shiftable on the pointer shaft it is usually desirable to fix the position of the pointer on the shaft so that thereafter no readjusting the code pattern occurs relative to the shaft and pointer. When it is necessary to test each of the register pointer shafts at each encoded dial position, substantial wear and extensive movement occurs in the lower decade order dial shafts when the higher and highest order dial shafts are rotated through the various dial positions. Also, with a fixed relationship established in the register gear train it is impossible to adjust one shaft independently of the other pointer shafts.
The present invention is directed to the aforementioned difficulties and disadvantages in manufacturing, testing and maintaining meter encoding registers made in accordance with the prior art arrangements.